1. Field of the Disclosure
The present invention relates to optical plates and backlight modules using optical plates.
2. Description of Related Art
A typical liquid crystal display (LCD) device includes an LCD panel, and a backlight module mounted behind the LCD panel for supplying light beams thereto. The backlight module mainly includes a light source and a plurality of optical elements arranged in an order to provide uniform illumination to the LCD panel.
Referring to FIG. 9, a typical backlight module 100 includes a frame 11, a plurality of illuminators 12, a first diffuser plate 13, an optical plate 10 and a second diffuser plate 14, arranged in that order from bottom to top. Referring also to FIG. 10, the optical plate 10 includes a main body 101 and a prism layer 103 formed on the main body 101. A plurality of V-shaped prisms 105 are formed at an outside surface of the prism layer 103. The first and the second diffuser plates 13, 14 are respectively used to scatter light beams transmitting therethrough. The optical plate 10 is used to control light beams transmitting therethrough to emit from the optical plate 10 along predetermined directions generally perpendicular to a liquid crystal panel (not shown) located above the backlight module 100, and used to converge the light beams toward a central region of the backlight module 100 for transmission to the liquid crystal panel.
However, the diffuser plates 13, 14 and the optical plate 10 absorb a portion of the light beams transmitting therethrough. In addition, an air gap typically exists at the interface between each of the diffuser plates 13, 14 and the optical plate 10, and the gapped interface results in some back reflection of light transmitting therethrough. For these reasons, the backlight module 100 typically has reduced light transmission and reduced brightness of light provided to the liquid crystal panel. That is, the utilization of light beams and the efficiency of the backlight module are limited.
What is needed, therefore, is a backlight module which can overcome the described limitations.